In theatrical, stage, and video productions, relatively short bursts of white light are sometimes used to mimic bolts of lightning, artillery fire and the like. In the prior art, bright flashes of light was produced by a manually operated scissors switch wherein a DC current was drawn between carbon electrodes and the switch was manually operated so as to draw and extinguish the arc in a manner more or less mimicking bolts of lightning.
This prior art technique suffers from a number of drawbacks. First, there is the obvious safety question of using a person to manually draw an arc using a scissors switch between two electrodes. Second, even when the scissors switch can be used safely, its use takes a toll on the DC generators used to produce the power to draw the arc, since the DC generator is essentially short circuited when the arc is drawn. Third, since the scissors switch is manually operated, the mimicked lightning bolts were not repeatable. Thus, for stage or theatrical productions, the lighting bolts would not be repeatable from performance to performance, and therefore they could not be easily timed to music or other events occurring during the performance. For movie or video work, when the same scene goes through a number of takes, each of the takes would have a different lightning display, thereby making it more difficult to edit the movie or video with scenes from different takes. There is no practicable way of varying the intensity of the flashes of light in the prior art to mimic, for example, intense nearby flashes of lightning and more distant flashes.
The present invention overcomes these difficulties by providing a lamp and driver circuitry for use therewith which can produce short, intense bursts of light or lower intensity bursts (if desired), such as what might be used to mimic bolts of lightning, in a manner which is safe, easily programmable and repeatable, and, moreover, does not require a DC generator and therefore does not adversely impact a DC generator. The lamp has an internal impedance so circuit is limited by the impedance.